Endocrine and therapeutic effects of aminoglutethimide in premenopausal patients with breast cancer.

Aminoglutethimide in combination with hydrocortisone provides an effective therapy in postmenopausal advanced breast cancer patients, with response rates of 37.5--50% having been found. Treatment with aminoglutethimide of only four premenopausal breast cancer patients has been reported in which two patients responded. The clinical and endocrine effects of 1000 mg aminoglutethimide daily and 20 mg hydrocortisone twice daily were studied in 18 premenopausal patients with breast cancer. Eight patients developed menstrual abnormalities, but there were no objective tumor responses in the 14 patients with assessable disease. Adrenal suppression was produced in all patients, with dehydroepiandrosterone sulfate levels suppressed to 20% of baseline values. Estrone and estradiol levels were not suppressed into the postmenopausal range. However, the therapeutic regime resulted in suppression of estrogen peaks after Pergonal administration, thus demonstrating a partial block of ovarian estrogen synthesis.